Ship with a protection system making it unsinkable

ABSTRACT

A watercraft, e.g. a passenger vessel, a ferry, a hazardous-substance freighter or the like, with a deck and with a buoyancy chamber in the deck, it being the case that, in a first operating state, the buoyancy chamber contains air, is characterized in that, in a second operating state, the buoyancy chamber is filled with a foam which has a high cell volume with closed cells and a dimensionally stable state of aggregation.

The present invention relates to a watercraft, e.g. a passenger vessel,a ferry, a hazardous-substance freighter or the like, with a deck andwith a buoyancy chamber in the deck, it being the case that, in a firstoperating state, the buoyancy chamber contains air.

Such watercraft are known from the general prior art, and are vessels,preferably relatively large vessels, with at least one deck and at leastone buoyancy chamber in the deck. During normal operation, a firstoperating state, of such vessels, the buoyancy chambers have beencalculated, and filled with ambient air, in accordance with a necessarybuoyancy volume. Rather than being restricted to their buoyancyfunction, the buoyancy chambers usually have very diverse functions.Every separated-off cavity on the ship can be used as a buoyancychamber, be this a cabin, a bunker, a stowage room or some other kind ofchamber. Buoyancy chambers which also have other functions thus alsocontain, in addition to the ambient air, features which serve forperforming these other functions.

In an emergency situation, a second operating state, as arises, forexample, in the event of underwater contact, there is threat of waterpenetrating by leakage. If this is the case, the penetrating water inthe corresponding buoyancy chambers displaces the ambient air. Thisproduces losses of buoyancy, which may result in the vessel completelysinking.

SUMMARY OF THE INVENTION

The object of the present invention is thus to provide a watercraft ofthe generic type mentioned in the introduction in which, when losses ofbuoyancy occur, the buoyancy can be stabilized immediately.

The object is achieved in that, in a second operating state, thebuoyancy chamber is filled with a foam which has a high cell volume withclosed cells and a dimensionally stable state of aggregation.

The term “buoyancy chamber” is used hereinbelow, and in the claims, tomean the chambers of a watercraft which, in a second operating state,serve as a stable buoyancy chamber.

The term “cell volume” is used hereinbelow, and in the claims, to mean alarge air-absorbing capacity either by virtue of a very large number ofsmall cells or by virtue of a very small number of large cells.

The filling of one or more buoyancy chambers with a dimensionally stablefoam with high cell volume if, in an emergency situation, waterthreatens to penetrate into buoyancy chambers means that thecorresponding buoyancy chambers cannot be flooded by water and, onaccount of the buoyancy volume maintained by the foam, maintain thebuoyancy function of the respective buoyancy chamber.

If the buoyancy chambers are multipurpose chambers, e.g. a cabin, it isadditionally ensured that the objects in the chamber are enclosed by thefoam and are thus protected against damage or loss.

It is advantageous for the buoyancy chamber to comprise a dischargearrangement which, during transition from the first operating state tothe second operating state, discharges the foam in an unstable state ofaggregation. This simplifies the filling of the respective buoyancychamber to a considerable extent. It is possible to spray or inject intothe buoyancy chamber, for example, foams in a liquid state ofaggregation which solidify in the ambient air and reach the stable stateof aggregation in a short period of time.

A further advantage is that there is provided a control arrangementwhich controls the discharge arrangement. Control of the dischargearrangement of each buoyancy chamber makes it possible to select quitespecifically discharge arrangements for discharging foam in general andfor discharging a metered quantity of foam in particular. This makes itpossible to stabilize the buoyancy at different locations of a vessel.

It is advantageous for it to be possible for the control arrangement tobe triggered manually in dependence on the detection of a loss ofbuoyancy. As a result, it is also possible for passenger cabins to beset in a second operating state as buoyancy chambers. Manual triggeringmakes it possible for the passenger cabin to be inspected carefully, andfor it to be ensured that there is no-one still left in the cabin, priorto the triggering operation.

A further advantage is that the control arrangement selects the deckwith the buoyancy chamber in dependence on the locality of the loss ofbuoyancy. This makes it possible for the buoyancy to be stabilizedspecifically in a deck-specific and loss-dependent manner.

A further advantage is that the control arrangement selects the buoyancychamber on the deck in dependence on the locality of the loss ofbuoyancy. This also makes it possible for the buoyancy to be stabilized,in addition, specifically in a chamber-specific and loss-dependentmanner.

It is advantageous for there to be provided a number of decks with anumber of chambers on which respectively selected chambers arepredetermined as the buoyancy chamber in each case. This makes itpossible to control the buoyancy very precisely over the entirewatercraft.

It is advantageous for each buoyancy chamber to be selected from a groupcomprising outlying cabins, lounges, bunkers, forechambers, aftchambers,stowage rooms and forepeak and steering gear. Utilization of all thefunctional chambers as buoyancy chambers makes it possible to ensureoptimum buoyancy in the event of an emergency.

A further advantage, is that, in its dimensionally stable state ofaggregation, the foam is pressure-resistant. This ensures that thebuoyancy chamber remains as such even in the case of elevated externalpressure.

It is advantageous for the foam to be a plastic foam which contains afoam stabilizer. The prior art discloses numerous plastic foams which,on account of the foam stabilizers, have the required features, highcell volume, pressure resistance and dimensional stability, with theresult that it is easy to make a suitable selection.

BRIEF DESCRIPTION OF THE DRAWINGS

An embodiment of the present invention is described in more detailhereinbelow with reference to the drawings, in which:

FIG. 1 shows a schematic view of a passenger vessel which is designedaccording to the invention;

FIG. 2 shows a schematic view of the passenger vessel from FIG. 1 withbuoyancy chambers foam-filled according to the invention;

FIG. 3 shows a schematic front view of the passenger vessel withchambers;

FIG. 4 shows a schematic front view of the passenger vessel from FIG. 2with buoyancy chambers foam-filled according to the invention;

FIG. 5 shows a schematic illustration of a control arrangement forfilling the buoyancy chambers of the passenger vessel with foam.

DESCRIPTION OF ILLUSTRATED EMBODIMENTS

FIG. 1 gives a schematic illustration of a passenger vessel as thewatercraft 1. In the present exemplary embodiment, the passenger vesselis to have a weight of approximately 4000 n.r.t. (net registered tons)and 6000 g.r.t. (gross registered tons). In a rescue situation in theevent of an accident or the like, the maximum mass which is to bebrought under control is approximately 4100 g.r.t. The buoyancy volumecomprising just two decks (passenger decks) 3 with a total ofapproximately 200 buoyancy chambers (cabins) 5 each having a buoyancyforce of 20 t is at least 4000 t. The buoyancy volumes of buoyancychambers fore and aft add up to at least 1000 t. This gives an overallbuoyancy volume of approximately 5000 t, that is to say a reservebuoyancy of at least 900 t.

A number of upper decks 7 are provided above the decks 3.

In FIG. 1, the watercraft 1 is operating normally; there is noemergency.

The waterline is designated 9 and located in a bottom region of the hull11.

In FIG. 2, the watercraft 1 is in a rescue situation, i.e. an emergencysituation. The waterline 9 is located in a top region of the hull 11.

It is illustrated schematically that the buoyancy chambers 5 of thepassenger decks, in particular the outer buoyancy chambers, have beenfilled with a foam (illustrated in black) 13. However, buoyancy chambersin the fore quarters 15 of the vessel and in the aft quarters 17 of thevessel have also been filled with foam.

FIG. 3 shows the watercraft 1 from the front. The buoyancy chambers 5inside the vessel are illustrated schematically. Theoretically, it ispossible for all buoyancy chambers 5 illustrated to be filled with afoam in the event of an emergency. In practice, however, a few buoyancychambers 5 are selected for this purpose. These buoyancy chambers 5 areillustrated in FIG. 4. For the passenger vessel used as an exemplaryembodiment, the outer cabins of all the (passenger) decks 3, the forequarters 15 of the ship and, likewise illustrated here, the steeringgear in the aft quarters 17 of the vessel each serve as buoyancy chamber5.

The upper decks 7 serve as escape decks.

A control arrangement 19 is illustrated schematically in FIG. 5. Thecontrol arrangement 19 controls a discharge arrangement 21, which isarranged in each of the buoyancy chambers 5 selected for the emergency.The discharge arrangement 21 is preferably a tank which is installed onthe ceiling of the respective buoyancy chamber 5 and in which the foamis stored in a dimensionally unstable, that is to say liquid or gaseous,state of aggregation. The ceiling installation ensures favourable,uniform filling of the buoyancy chamber.

Arranged in a command center, e.g. on the bridge of the passengervessel, is an emergency switch 23 which is operatively connected to agas-pressure generator 27 via a line 25. The gas-pressure generator 27is operatively connected, via a system of lines 29, 30 with a valvearrangement 31, e.g. a solenoid valve, to each discharge arrangement 21in each buoyancy chamber 5.

In addition, the valve arrangement 31 is operatively connected to asafety switch 35 via a further line 33.

In the event of an emergency situation, the emergency switch 23 isactuated. As a result, the gas-pressure generator 27 generates a gaspressure in the system of lines 29, 30. If the selected buoyancychambers 5 are passenger cabins or chambers in which there may bepeople, the buoyancy chambers 5 are inspected by the staff. If the staffestablish that a buoyancy chamber 5 is empty, the safety switch 35 isactuated, as a result of which the valve arrangement 31 opens and thegas pressure in the line 30 is transmitted to the discharge arrangement21. As a result, the foam, which is present in the dimensionallyunstable state of aggregation, is driven out of the dischargearrangement 21 and sprayed or injected into the buoyancy chamber 5. Thefoam solidifies in ambient air with the already mentioned properties andensures the buoyancy function of the corresponding buoyancy chamber 5.

The control arrangement 19 may be designed such that certain decks 3 andbuoyancy chambers 5 can be targeted quite specifically, via the systemof lines 29, 30, in dependence on the locality of a loss of buoyancy.

The foam may be a mineral or organic natural foam or plastic foam withor without a foam stabilizer. Foams with the abovementioned propertiesare known in general from the prior art, so these will not be describedin any more detail here.

Upon actuation, the safety switch 35 closes a circuit for triggering thevalve arrangement and, at the same time, opens a network circuit for thecorresponding buoyancy chamber.

What is claimed is:
 1. A watercraft, comprising a deck and a buoyancychamber in the deck, wherein in a first operating state, the buoyancychamber contains air, and in a second operating state, the buoyancychamber is filled with a foam which has a high cell volume with closedcells and a dimensionally stable state of aggregation.
 2. A watercraftaccording to claim 1, wherein the buoyancy chamber comprises a dischargearrangement which, during transition from the first operating state tothe second operating state, discharges the foam in a dimensionallyunstable state of aggregation.
 3. A watercraft according to claim 2,further comprising a control arrangement for controlling the dischargearrangement.
 4. A watercraft according to claim 3, wherein the controlarrangement is triggered manually in dependence on the detection of aloss of buoyancy.
 5. A watercraft according to claim 4, wherein thecontrol arrangement selects the deck with the buoyancy chamber independence on the locality of the loss of buoyancy.
 6. A watercraftaccording to claim 4, wherein the control arrangement selects thebuoyancy chamber on the deck in dependence on the locality of the lossof buoyancy.
 7. A watercraft according to claim 1, further comprising aplurality of decks with a number of chambers in which respectivelyselected chambers are predetermined as the buoyancy chamber in eachcase.
 8. A watercraft according to one of the preceding claims,characterized in that each buoyancy chamber (5) is selected from a groupcomprising cabins, lounges, bunkers, forechambers, aftchambers, stowagerooms, forepeak and steering gear.
 9. A watercraft according to claim 1,wherein in its dimensionally stable state of aggregation, the foam ispressure-resistant.
 10. A watercraft according to claim 1, wherein thefoam is a plastic foam which contains a foam stabilizer.